Day 21 (Day23 on notes)

Today we went over how OP Amps work in AC circuit, and did the Inverting Voltage Amplifier Lab and the Relaxation Oscillator lab to see how to see how they would work in real life.

Here we did an example of an op amp in the frequency domain.

Inverting Voltage Amplifier Lab:

The purpose of this lab is to see the amplitude gain and phase difference between the output and input signals of a inverting voltage amplifier circuit.

Our theoretical values for gain and phase shift are on the right side on the right side of the picture in the pre lab section. 
For our results shown in pink, we got a fairly close to zero percent difference for the 100 and 1000 Hz. For the 5kHZ we had a substantially higher error in gain which may be due to the op amp working outside of its frequency range.


Input wave is at 100Hz at 2V shown in orange and the output wave is in blue.

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Input wave is at 1kHz at 2V shown in orange and the output wave is in blue.


Finally, here is the input wave is at 5kHz at 2V shown in orange and the output wave is in blue.

Here is a picture of our circuit.

Op Amp Relaxation Oscillator Lab:
The purpose of this lab is to construct a relaxation oscillator, which is a type of device that will act as a switch when a certain voltage is applied to one of its terminals. This voltage is usually the voltage across a capacitor that is being charged or discharged.


Here are the predictions according to Everycircuit.


Above is what we measured with the oscilloscope with an input of 733 Hz at 2V.

There is rounding error when we measured the pots resistance with the multimeter so we were not able to get the exact value. Also we treat the op amp as ideal so that too may contribute to our fairly high error calculated above.